package com.myblog.myblog.util;


import org.commonmark.Extension;
import org.commonmark.ext.gfm.tables.TableBlock;
import org.commonmark.ext.gfm.tables.TablesExtension;
import org.commonmark.ext.heading.anchor.HeadingAnchorExtension;
import org.commonmark.node.Image;
import org.commonmark.node.Link;
import org.commonmark.node.Node;
import org.commonmark.parser.Parser;
import org.commonmark.renderer.html.AttributeProvider;
import org.commonmark.renderer.html.AttributeProviderContext;
import org.commonmark.renderer.html.AttributeProviderFactory;
import org.commonmark.renderer.html.HtmlRenderer;

import java.util.*;


public class MarkdownUtils {
    public static String markdownToHtml(String markdown){
        Parser parser = Parser.builder().build();
        Node document = parser.parse(markdown);
        HtmlRenderer renderer = HtmlRenderer.builder().build();
        return renderer.render(document);  // "<p>This is <em>Sparta</em></p>\n"
    }
    public static String markdownToHtmlExtensions(String markdown){
        //h标签生成id
        Set<Extension> headingAnchorExtensions = Collections.singleton(HeadingAnchorExtension.create());
        //转换table的HTML
        List<Extension> extensions = Arrays.asList(TablesExtension.create());
        Parser parser = Parser.builder()
                .extensions(extensions)
                .build();
        Node document = parser.parse(markdown);
        HtmlRenderer renderer = HtmlRenderer.builder()
                .extensions(headingAnchorExtensions)
                .extensions(extensions)
                .attributeProviderFactory(new AttributeProviderFactory() {
                    public AttributeProvider create(AttributeProviderContext context) {
                        return new CustomAttributeProvider();
                    }
                })
                .build();
        return renderer.render(document);
    }

    static class CustomAttributeProvider implements AttributeProvider{
        @Override
        public void setAttributes(Node node, String tagName, Map<String, String> attributes) {
            //改变a标签的target的属性为——blank
            if (node instanceof Link) {
                attributes.put("target", "_blank");
            }
            if (node instanceof TableBlock) {
                attributes.put("class", "table table-bordered");
            }
        }
    }
    public static void main(String[] args){
        String table = "| 1 | 2 | 3 |\n" +
                "| 1 | 2 | 3 |\n" +
                "| 1 | 2 | 3 |\n" +
                "| 1 | 2 | 3 |\n" +
                "\n";
        String a = "[aa](http://www.lirenmi.cn)";
        System.out.println(markdownToHtmlExtensions(table));
    }


}
